Robotic system

ABSTRACT

The invention relates to a robotic system for moving a shapeable instrument like a shapeable catheter within an object like a person. The system ( 1 ) comprises a robotic device ( 2, 3 ) for modifying the shape of the instrument ( 2 ) and moving the instrument within the object ( 7 ) and a control unit ( 4 ) for controlling the robotic device based on structure information like a roadmap, a target position and shape and an actual position and shape such that the instrument is moved and the shape of the instrument is modified from the actual position and shape to the target position and shape. Since the control unit considers structure information while controlling the robotic device, the navigation of the instrument can be automatically performed under consideration of knowledge about regions within the object, through which the instrument is navigatable. The navigation may therefore be performed without or with few user interactions only.

CROSS-REFERENCE TO PRIOR APPLICATIONS

This application is the U.S. National Phase application under 35 U.S.C.§ 371 of International Application Serial No. PCT/EP2014/067788, filedon Aug. 21, 2014, which claims the benefit of European PatentApplication No. 13182929.3, filed on Sep. 4, 2013.

These applications are hereby incorporated by reference herein.

FIELD OF THE INVENTION

The invention relates to a robotic system, a robotic method and acomputer program for moving a shapeable instrument within an object.

BACKGROUND OF THE INVENTION

If a medical robotic system for navigating a shapeable interventionalinstrument within a person, in particular, within a vessel of theperson, like the Magellan robotic system from the company Hansen is usedby a physician, the physician has to control the medical robotic systemsuch that the interventional instrument reaches a desired target regionwithin the person. This control of the medical robotic system requires alot of user interactions, which makes the interventional procedurerelatively cumbersome for the physician.

The US 2011/0319815 A1 discloses a fiber optic instrument sensing systemthat improves control of a shapeable or steerable instrument using shapedata. Additional systems use such shape data for improved mapping oradjusting models of the instrument. Such systems include robotic medicalsystems for controlling a shapeable instrument within an anatomicalregion having a controller, one or more actuators, and a localizationsystem for guiding one or more shapeable instruments.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a robotic system, arobotic method and a computer program for moving a shapeable instrumentwithin an object, which allow for a reduction of user interactions whilenavigating the shapeable instrument within the object.

In a first aspect of the present invention a robotic system for moving ashapeable instrument within an object is presented, wherein the systemcomprises:

a robotic device for modifying the shape of the instrument and movingthe instrument within the object,

an inner structure providing unit for providing structure informationabout the inner structure of the object,

a target position and shape providing unit for providing a targetposition and shape of the instrument within the object,

an actual position and shape providing unit for providing the actualposition and shape of the instrument within the object,

a control unit for controlling the robotic device based on the structureinformation, the target position and shape of the instrument and theactual position and shape of the instrument such that the instrument ismodified and moved from the actual position and shape to the targetposition and shape,

wherein the inner structure providing unit is further adapted toindicate safety zones within the inner structure, in which the roboticdevice should not apply forces for modifying the shape of the instrumentand/or moving the instrument within the object, which are larger than apredefined force value, wherein the control unit is adapted to controlthe robotic device such that no forces are applied in the safety zonesbeing larger than the predefined force value, while the shape of theinstrument is modified and the instrument is moved from the actualposition and shape to the target position and shape.

Since the control unit considers the structure information whilecontrolling the robotic device, the navigation of the instrument withinthe object from the actual position and shape of the instrument to thetarget position and shape of the instrument can be automaticallyperformed under consideration of knowledge about regions within theobject, through which the instrument is navigatable. The navigation ofthe instrument within the object can therefore be performed with lessuser interactions, in particular, without any user interaction.

The object is preferentially a living object like a person or an animaland the shapeable instrument is preferentially an interventionalinstrument for performing an interventional procedure. For instance, theshapeable instrument is a shapeable catheter, in particular, a shapeablemicrocatheter, a shapeable needle, a shapeable endoscope or any othertype of shapeable medical device.

The robotic device and the instrument can be integrated such that theinstrument comprises several portions, which are connected by hingessuch that the portions are pivotable with respect to each other by therobotic device by using, for instance, wires, which can be connected tomotors of the robotic device for allowing the motors to change the shapeof the instrument. The robotic device can comprise at least two furthermotors for translating the entire instrument and for rotating the entireinstrument. In particular, for translating and rotating the entireinstrument the robotic device may comprise a mechanical fixture forclamping the instrument, wherein the at least two further motors may beadapted to translate the mechanical fixture along a rail and to rotatethe mechanical fixture. The robotic device may also be configured suchthat the instrument is rotated within the mechanical fixture by using atleast one of the further motors. The motors of the robotic device may becontrolled by the control unit, in order to modify the shape of theinstrument and move the instrument based on the structure information,the target position and shape of the instrument and the actual positionand shape of the instrument.

The inner structure providing unit can be a storing unit, in which thestructure information is stored already and from which the structureinformation can be retrieved for providing the same. However, the innerstructure providing unit can also be adapted to determine the structureinformation based on, for instance, an image of the object like acomputed tomography image or a magnetic resonance image which may beacquired before the instrument is introduced into the object and/orafter the instrument has been introduced into the object, i.e. pre-and/or intra-procedural, or the structure information can directly bethe image of the object, which may be regarded as being a structureimage. In particular, the inner structure providing unit can be adaptedto generate a roadmap based on an image of the object and to providethis roadmap as the structure information, wherein the roadmap definesinner paths of the object, along which the instrument is movable.

The predefined force value can be zero indicating that no force shouldbe applied in the safety zones. The safety zones are, for instance,zones close to the inner walls of the object or areas of hightortuosity. This allows automatically or semi-automatically navigatingthe instrument within the object with increased caution, therebydecreasing the likelihood of unwanted damages of the inner structure.

The target position and shape providing unit can be a storing unit, inwhich the target position and shape is stored already and from which thetarget position and shape can be retrieved for providing the same.However, the target position and shape providing unit can also beadapted to determine the target position and shape of the instrumentwithin the object based on, for instance, the provided structureinformation and to provide the determined target position and shape.

The robotic system may further comprise a target region providing unitfor providing a target region to which the instrument is to be moved,wherein the target position and shape providing unit may be adapted todetermine the target position and shape of the instrument within theobject based on the target region and the structure information. Inparticular, the target region providing unit may be adapted to allow auser to input the target region. For instance, the target regionproviding unit can be adapted to allow a user to input target landmarkslike target rings, wherein the target position and shape providing unitcan be adapted determine the target position and shape depending on theinput target landmarks or target rings and the structure information. Inparticular, the user may just input, to which location the instrumentshould be moved, whereupon the target position and shape providing unitdetermines the target position and shape accordingly and the controlunit controls the robotic device such that the input location is reachedby the instrument. The target position and shape providing unit may befurther adapted to allow the user to modify the target position andshape of the instrument.

The target position and shape providing unit can be adapted to providetarget rules defining positions and shapes of the instrument dependingon structure information and optionally on further features like atarget region and to determine the target position and shape of theinstrument depending on the structure information, the optional furtherfeatures and on the target rules. The target rules can define, forinstance, that the instrument should be perpendicular to an inner ringstructure through which the instrument is to be navigated, that theinstrument should have a certain distance to inner walls of the object,that in certain zones within the object, which may be indicated in thestructure information, strong forces should not be applied, et cetera.The target position and shape can be determined such that theseconditions are fulfilled.

In an embodiment the inner structure providing unit is adapted toprovide a structure image, which shows the inner structure, as thestructure information and the target position and shape providing unitis adapted to a) allow a user to add markers to the structure image andb) determine the target position and shape of the instrument within theobject based on the added markers. This allows the user to determine thetarget position and shape, wherein then the control unit can, especiallyautomatically, control the robotic device such that the instrument ispositioned and shaped in accordance with the user-determined targetposition and shape. For example, a user may add several markers, whichcan be automatically connected by the target position and shapeproviding unit for determining the target position and shape.

The structure image may be any image showing the inner structure of theobject like a magnetic resonance image, a computed tomography image, anultrasound image or any other medical image showing the inner structureof the object. The structure image can also be an image, which shows theinner structure and which is derived from a medical image, like aroadmap derived from, for instance, a computed tomography image or amagnetic resonance image.

In a further embodiment the actual position and shape providing unit andthe control unit are adapted to provide a feedback loop during amovement of the instrument within the object, wherein the actualposition and shape of the instrument is continuously updated and therobotic device is continuously controlled based on the structureinformation, the target position and shape of the instrument and theupdated actual position and shape of the instrument. Thus, it can becontinuously reacted on the actual position and shape of the instrument,which may be different to what would be expected in view of the intendedposition and shape of the instrument because of, for instance,inaccuracies in steering the instrument. A correction loop can thereforebe provided, which leads to a more accurate navigation of the instrumentwithin the object.

In an embodiment, alternatively or in addition, the inner structureproviding unit and the control unit can be adapted to provide a feedbackloop during a movement of the instrument within the object, wherein theinner structure of the object is continuously updated and the roboticdevice is continuously controlled based on the updated structureinformation, the target position and shape of the instrument and theactual position and shape of the instrument. This allows the controlunit to consider changes of the inner anatomy of the object, which maybe caused by the instrument within the object, during the interventionalprocedure. Also this leads to a correction loop, which can allow for amore accurate navigation of the instrument within the object.

It is preferred that the control unit is adapted to a) determine aposition and shape plan defining a modification of the shape and amovement of the instrument, which is required for arranging theinstrument in accordance with the target position and shape, dependingon the structure information, the target position and shape of theinstrument and the actual position and shape of the instrument, and b)control the robotic device in accordance with the determined positionand shape plan. The position and shape plan may explicitly or implicitlydefine translations and/or rotations of the entire instrument and/or ofportions of the instrument. For instance, rotations between differentportions of the instrument and translations and/or rotations of theentire instrument can be defined by the position and shape plan fordefining a modification of the shape and a movement of the instrument,which is required for arranging the instrument in accordance with thetarget position and shape.

In an embodiment the inner structure providing unit is adapted toprovide a structure image, which shows the inner structure, as thestructure information, wherein element weights are assigned to elementsof the structure image, wherein the control unit is adapted to determinethe position and shape plan such that a plan weight, which depends onthe element weights assigned to the elements of the structure image thatcorrespond to regions within the object at least temporarily occupied bythe instrument when performing the position and shape plan, isoptimized. For instance, the plan weight can be the sum of the elementweights assigned to the elements of the structure image that correspondto regions within the object at least temporarily occupied by theinstrument when performing the position and shape plan. The elements ofthe structure image are preferentially voxels, wherein the structureimage may be a roadmap, a computed tomography image, a magneticresonance image, an image showing a model of the inner structure, etcetera.

The control unit may be adapted to determine several position and shapeplans, wherein the system may further comprise a display for displayingthe determined position and shape plans together with the innerstructure of the object as defined by the provided structure informationand wherein the control unit may be adapted to provide a user interfaceallowing the user to select one of the determined position and shapeplans and to control the robotic device in accordance with the selectedposition and shape plan. Thus, a user may select a desired position andshape plan, whereupon the instrument can be automatically navigated suchthat it is moved and its shape is modified from the actual position andshape to the target position and shape in accordance with the selectedposition and shape plan.

In an embodiment the position and shape plan explicitly or implicitlydefines planned intermediate positions and shapes of the instrument,which are planned to be used while the shape of the instrument ismodified and the instrument is moved from the actual position and shapeto the target position and shape and which correspond to translationand/or rotation steps of the entire instrument and/or of portions of theinstrument for reaching the planned intermediate positions and shapes ofthe instrument, wherein the actual position and shape providing unit isadapted to continuously update the actual position and shape of theinstrument while the shape of the instrument is modified and theinstrument is moved in accordance with the position and shape plan andwherein the control unit is adapted to modify the position and shapeplan, if during the modification of the shape of the instrument and themovement of the instrument in accordance with the position and shapeplan a deviation between an expected planned intermediate position andshape of the instrument and the updated actual position and shape of theinstrument is larger than a predefined threshold, based on the structureinformation, the target position and shape and the updated actualposition and shape of the instrument. Thus, during the navigationprocess the actual position and shape of the instrument can be monitoredand if the monitored actual position and shape deviates from theexpected planned intermediate position and shape of the instrument, theposition and shape plan can be automatically updated and the navigationprocess can continue in accordance with the updated position and shapeplan. The modification, i.e. the updating, of the position and shapeplan can be performed by re-calculating the position and shape planbased on the updated actual position and shape of the instrument, thetarget position and shape and the structure information.

The control unit may be adapted to allow a user to interrupt the controlof the robotic device. For instance, the control unit can be adapted tocontrol the robotic device only, if a user inputs a signal indicatingthat the control unit is allowed to control the robotic device based onthe structure information, the target position and shape of theinstrument and the actual position and shape of the instrument. Inparticular, the control unit can be adapted to control the roboticdevice only, if a switch like a hand switch or a foot switch iscontinuously pressed. These limited user interactions allow the user toinfluence the navigation procedure, wherein still the number of userinteractions is relatively small.

In an embodiment the actual position and shape providing unit is adaptedto provide the position and shape of the entire instrument. Consideringthe position and shape of the entire instrument, and not only of one orseveral parts of the instruments, during the navigation procedure canimprove the accuracy of the navigation procedure.

The actual position and shape providing unit is preferentially adaptedto provide the position and shape of the instrument by optical shapesensing (OSS). This allows providing the position and shape of theinstrument with high accuracy, without requiring the user to performcumbersome tracking procedures that may use further devices forproviding, for instance, a navigation field like an electromagneticfield as needed in case of electromagnetic tracking.

In another aspect of the present invention a robotic method for moving ashapeable instrument within an object is presented, wherein the methodcomprises:

providing structure information about the inner structure of the objectby an inner structure providing unit,

providing a target position and shape of the instrument within theobject by a target position and shape providing unit,

providing the actual position and shape of the instrument within theobject by an actual position and shape providing unit,

controlling a robotic device, which is configured to modify the shape ofthe instrument and move the instrument within the object, based on thestructure information, the target position and shape of the instrumentand the actual position and shape of the instrument by a control unitsuch that the instrument is modified and moved from the actual positionand shape to the target position and shape,

indicating safety zones within the inner structure, in which the roboticdevice should not apply forces for modifying the shape of the instrumentand/or moving the instrument within the object, which are larger than apredefined force value, and

controlling the robotic device such that no forces are applied in thesafety zones being larger than the predefined force value.

In a further aspect of the present invention a computer program formoving a shapeable instrument within an object is presented, wherein thecomputer program comprises program code means for causing a roboticsystem as defined in claim 1 to carry out the steps of the roboticmethod as defined in claim 13, when the computer program is run on acomputer controlling the robotic system.

It shall be understood that the robotic system of claim 1, the roboticmethod of claim 13, and the computer program of claim 14 have similarand/or identical preferred embodiments, in particular, as defined in thedependent claims.

It shall be understood that a preferred embodiment of the invention canalso be any combination of the dependent claims or above embodimentswith the respective independent claim.

These and other aspects of the invention will be apparent from andelucidated with reference to the embodiments described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following drawings:

FIG. 1 shows schematically and exemplarily an embodiment of a roboticsystem for moving a shapeable instrument within a person,

FIG. 2 schematically and exemplarily illustrates a roadmap, a targetposition and shape of the instrument, an actual position and shape ofthe instrument and target regions, and

FIG. 3 shows a flowchart exemplarily illustrating an embodiment of arobotic method for moving the shapeable instrument within the person.

DETAILED DESCRIPTION OF EMBODIMENTS

FIG. 1 shows schematically and exemplarily an embodiment of a roboticsystem for moving a shapeable instrument within an object. In thisembodiment the robotic system 1 is adapted to move a shapeable catheter2 within a person 7 lying on support means 8 like a patient table. Theshapeable catheter 2 comprises several portions, which are connected byhinges such that the portions are pivotable with respect to each otherby using wires connected to the respective portions. In particular, oneend of a respective wire is connected to a respective portion of thecatheter 2 and the other end of the respective wire is connected to arespective motor of a steering unit 3 such that the different portionsof the catheter 2 can be pivoted with respect to each other via thewires and the motors in the steering unit 3. The steering unit 3 can beattached to the support means 8 via a rigid mechanical connection 20.The steering unit 3 comprises at least two further motors fortranslating the entire catheter 2 and for rotating the entire catheter2. In particular, for translating and rotating the entire catheter 2 thesteering unit 3 comprises a mechanical fixture for clamping the catheter2, wherein the at least two further motors are adapted to translate themechanical fixture along a rail and to rotate the mechanical fixture. Asan alternative to rotating the mechanical fixture, the steering unit 3may be configured such that the catheter 2 is rotated within themechanical fixture by using at least one of the further motors.Generally, mechanical configurations of known robotic systems can beused for modifying the shape of the catheter and moving the catheterlike the mechanical configuration of the Magellan robotic system fromthe company Hansen.

The steerable catheter 2 and the steering unit 3 can be regarded asforming a robotic device for modifying the shape of the catheter 2 andfor moving the catheter 2 within the person 7.

The robotic system 1 further comprises an inner structure providing unit5 for providing structure information about the inner structure of theperson 7. In this embodiment the inner structure providing unit isadapted to provide a roadmap showing anatomical constraints, wherein theroadmap defines the regions within the person 7, through which thecatheter 2 can be navigated. The roadmap can have been determined basedon a medical image of the person 7 like a computed tomography image or amagnetic resonance image, which may have been acquired before thecatheter 2 has been introduced into the person 7 or after the catheter 2has been introduced into the person 7, i.e. the medical image can be apre- or intra-procedural image. The inner structure providing unit 5 isfurther adapted to indicate safety zones within the inner structure byindicating these zones on the roadmap. The indicated safety zones defineregions within the person 7, in which the robotic device 2, 3 should notapply forces for modifying the shape of the catheter 2 and/or for movingthe catheter 2 within the person 7, which are larger than a predefinedforce value. In an embodiment the predefined force value is zeroindicating that no force should be applied in the safety zones. Thesafety zones are, for instance, zones close to inner walls of vessels orother lumina within the person or areas of high tortuosity. The safetyzones can be predefined, for instance, manually predefined. However, thesafety zones can also be automatically determined by applyingpredefining safety rules to the roadmap, wherein the predefined safetyrules can define the safety zones based on features of the innerstructure like positions of inner walls within the person. For example,the safety rules can define that the safety zones are zones adjacent toinner walls of vessels or other lumina within the person 7, i.e. zoneswithin a predefined safety distance to the inner walls. Furthermore, inan embodiment different kinds of safety zones with different safetylevels can be defined, wherein to each safety level a certain forcevalue can be predefined such that in some safety zones no forces shouldbe applied and in other safety zones small forces are allowed.

The robotic system further comprises a target region providing unit 6for providing a target region to which the catheter 2 is to be moved anda target position and shape providing unit 9 for providing a targetposition and shape of the catheter 2 within the person 7, wherein thetarget position and shape providing unit 9 is adapted to determine thetarget position and shape of the catheter 2 within the person 7 based onthe target region and the roadmap. In this embodiment the target regionproviding unit 6 is adapted to allow a user to input the target regionon the roadmap. For instance, the target region providing unit 6 canprovide a graphical user interface, which allows the user to input thetarget region via an input unit 11 like a keyboard, a computer mouse, atouch screen, et cetera and via a display 12 showing the roadmap. Thetarget region providing unit 6 may also be adapted to allow the user toindicate the target region on another medical image not being theroadmap like a computed tomography image or a magnetic resonance image,wherein in this case this other medical image and the roadmap areregistered with respect to each other such that the location of theinput target region is known with respect to the roadmap.

The target region input by the user can be a target ring enclosing avessel opening, through which the catheter 2 should be navigated, or thetarget region can be another landmark. The target position and shapeproviding unit 9 is adapted to provide target rules defining positionsand shapes of the catheter depending on structure information anddepending on target regions. The target rules can define, for instance,that the catheter should be perpendicular to an inner ring structurethrough which the catheter is to be navigated, that the catheter shouldhave a certain distance to inner walls of vessels or other lumina of theperson, that in certain zones, i.e. the safety zones, within the personstrong forces should not be applied, et cetera. The target position andshape providing unit 9 is preferentially adapted to calculate the targetshape and position of the catheter 2 based on the roadmap and the inputtarget region such that the target rules are fulfilled.

The target position and shape providing unit 9 is further adapted toallow the user to modify the target position and shape of the catheter.Thus, the target position and shape providing unit 9 can also be adaptedto provide a graphical user interface allowing the user to modify thecalculated target position and shape of the catheter 2 by using theinput unit 11 and the display 12 on which the target position and shapemay be shown together with the roadmap and/or a medical image.

The robotic system 1 further comprises an actual position and shapeproviding unit 10 for providing the actual position and shape of thecatheter 2 within the person 7. In this embodiment the catheter 2 isequipped with an OSS fiber, which is connected to the actual positionand shape providing unit 10 for providing the actual position and shapeof the catheter 2 within the person 7 by using OSS. For determining theactual position and shape of the catheter 2 within the person 7 knownOSS techniques can be used like the technique disclosed in U.S. Pat. No.7,772,541 B2, which is herewith incorporated by reference. The actualposition and shape providing unit 10 is adapted to provide the positionand shape of the entire catheter 2 and not only of certain portions ofthe catheter 2.

The robotic system 1 further comprises a control unit 4 for controllingthe robotic device 2, 3 based on the roadmap, the target position andshape of the catheter 2 and the actual position and shape of thecatheter 2. In particular, the control unit 4 is adapted to determine aposition and shape plan defining a modification of the shape and amovement of the catheter 2, which is required for arranging the catheter2 in accordance with the target position and shape, depending on theroadmap, the target position and shape of the catheter 2 and the actualposition and shape of the catheter 2 and to control the robotic device2, 3, in particular, the motors of the steering unit 3, in accordancewith the determined position and shape plan. The control unit 4 can beadapted to determine the position and shape plan by determining plannedintermediate positions and shapes of the catheter 2, which are plannedto be used while the shape of the catheter 2 is modified and thecatheter 2 is moved from the actual position and shape to the targetposition and shape, wherein the actual position and shape providing unit10 can be adapted to continuously update the actual position and shapeof the catheter 2 while the shape of the catheter 2 is modified and thecatheter 2 is moved in accordance with the position and shape plan andwherein the control unit 4 can be adapted to modify the position andshape plan, if during the modification of the shape of the catheter 2and the movement of the catheter 2 in accordance with the position andshape plan a deviation between an expected planned intermediate positionand shape of the catheter 2 and the updated actual position and shape ofthe catheter 2 is larger than a predefined threshold, based on theroadmap, the target position and shape and the updated actual positionand shape of the catheter 2. Thus, the actual position and shapeproviding unit 10 and the control unit 4 are preferentially adapted toprovide a feedback loop, while the catheter 2 is moved and the shape ofthe catheter 2 is modified within the person 7, wherein the actualposition and shape of the catheter 2 is continuously updated and themotors of the steering unit 3 are continuously controlled based on theroadmap, the target position and shape of the catheter 2 and the updatedactual position and shape of the catheter 2, wherein the position andshape plan is continuously updated based on the updated actual positionand shape of the catheter 2 and the control unit 4 controls the roboticdevice 2, 3 in accordance with the updated position and shape plan.

The position and shape plan can define translations and rotations of theentire catheter 2 and rotations of portions of the catheter 2 withrespect to each other for modifying the shape of the catheter 2 suchthat the planned intermediate positions and shapes and finally thetarget position and shape are reached. The position and shape plan canbe executed by providing corresponding commands to be sent to the motorsof the steering unit 3, wherein the commands prompt the motors to moveand modify the shape of the catheter 2 such that the plannedintermediate positions and shapes and finally the target position andshape are reached. The control unit 4 can be adapted to determine theposition and shape plan based on predefined plan rules defining theposition and shape plan depending on the respective target position andshape, the actual position and shape and the roadmap. For instance, theplan rules can define that, if the target region is defined by a targetring, the target ring has to be perpendicularly approached by theinstrument and/or that in the safety zones no forces are allowed to beapplied, which are larger than the predefined force value, inparticular, that, if the force value is zero, the instrument is notallowed to be moved through the safety zones. Correspondingly, the planrules can define that, if a sequence of target rings has been provided,the target rings have to be perpendicularly approached by the instrumentand/or that in the safety zones no forces are allowed to be applied,which are larger than the predefined force value, in particular, that,if the force value is zero, the instrument is not allowed to be movedthrough the safety zones. The plan rules can further define that theshape modifications and the movements can only take place within thelumina indicated on the roadmap. Moreover, further possible plan rulescan define that a vessel opening should be approached perpendicular to atransversal plane of the vessel opening and/or the target position andshape should be reached with a minimum number of shape modifications andmovements of the catheter, et cetera.

Alternatively or in addition, element weights like risk values can beassigned to elements of the roadmap, in particular, to voxels of theroadmap, and the plan rules can define that the position and shape planshould be determined such that a plan weight, which depends on the sumof the element weights assigned to the elements of the roadmap thatcorrespond to regions within the person 7 at least temporarily occupiedby the catheter 2 when performing the position and shape plan, isoptimized, particularly minimized. For instance, several position andshape plans can be determined based on plan rules defining that, if thetarget region is defined by a target ring, the target ring has to beperpendicularly approached by the instrument and/or that in the safetyzones no forces are allowed to be applied, which are larger than thepredefined force value, and/or that the shape modifications and themovements can only take place within the lumina indicated on theroadmap, and/or that a vessel opening should be approached perpendicularto a transversal plane of the vessel opening, et cetera, wherein theplan rules can further define that from these determined position andshape plans the position and shape plan is selected having the optimumplan weight, particularly having the smallest plan weight. The controlunit 4 can also be adapted to allow the user to select a desiredposition and shape plan. In particular, the determined position andshape plans can be shown together with the roadmap on the display 12 andthe control unit 4 can be adapted to provide a graphical user interfaceallowing the user to select one of the determined position and shapeplans and to control the robotic device 2, 3 in accordance with theselected position and shape plan.

The control unit 4 may be adapted to allow the user to interrupt theautomatic control of the steering unit 3. In particular, the controlunit 4 may be adapted to control the steering unit 3 only, if the userinputs a signal indicating that the control unit 4 is allowed to controlthe steering unit 3 based on the roadmap, the target position and shapeof the catheter 2 and the actual position and shape of the catheter 2.For instance, the control unit 4 can be adapted to control the steeringunit 3 only, if a switch at the input unit 11 or another switch ispressed, wherein the control is interrupted, if the switch is notpressed. The switch may be a hand switch or a foot switch. If therobotic system is not automatically controlled, the user may control theposition and shape of the catheter 2 by using the input unit 11, whilethe road map, the actual position and shape of the catheter 2 and thetarget region are shown on the display 12.

FIG. 2 illustrates schematically and exemplarily a roadmap 13 with twotarget rings 16, 17, through which the catheter 2 should be navigated,the target position and shape 14 of the catheter 2 and the actualposition and shape 15 of the catheter 2.

In the following an embodiment of a robotic method for moving ashapeable instrument within an object will exemplarily be described withreference to a flowchart shown in FIG. 3.

In step 101 the inner structure providing unit 5 provides the roadmap 13showing the inner structure of the person 7 and in step 102 the targetposition and shape providing unit 9 provides the target position andshape 14 of the catheter 2 within the person 7. The target position andshape 14 can be provided, for instance, based on target rings 16, 17 andthe roadmap 13 by the target position and shape providing unit 9. Instep 103 the actual position and shape 15 of the catheter 2 within theperson 7 is determined by the actual position and shape providing unit10 by using OSS and in step 104 the steering unit 3 is controlled by thecontrol unit 4 depending on the roadmap 13, the target position andshape 14 of the catheter 2 and the actual position and shape 15 of thecatheter 2. Steps 103 and 104 are performed in a loop such that thecontrol of the steering unit 3 can consider updated actual positions andshapes of the catheter 2 as a feedback. If the user interrupts thecontrolling process or if the catheter 2 has reached the target positionand shape, the method ends in step 105.

The robotic system and method described above with reference to FIGS. 1and 3 derive a target position and shape based on one or severaltargets, i.e. one or several target regions, and based on an anatomicalconstraint roadmap. The control unit 4, which can also be regarded asbeing a motor control, uses these inputs along with the continuouslymonitored actual position and shape, in order to navigate the catheterwithin the person with no or with only few user interactions. The fewuser interactions may include a modification of the target position andshape, an interruption of the motor drive, wherein the motor drive mayonly be enabled when a foot switch or a hand switch is continuouslypressed, and restarting the target planning, i.e. restarting thedetermination of the position and shape plan.

The roadmap can be generated from pre- and/or intra-procedural medicaldata. To provide a safe control of the robotic system, the road map canhave zones where strong force is inadvisable, for example, close to theinner walls, in areas of high tortuosity and in anatomically unsafeareas, i.e. in areas which are known to be easily damaged because of aknown weakness.

The target position and shape can be derived from the planninginformation, i.e., for instance, from the input target region, from theroadmap or from another anatomical context in the same frame ofreference. The target region can, for instance, be created by allowing auser to add targeting landmarks or rings to the roadmap or otheranatomical data like medical images shown on the display 12, wherein atarget position and shape can be plotted on the display 12 depending onthe anatomical context, for instance, the roadmap or another anatomicalinformation, and on the target region, for instance, the target rings.

The position and shape plan can be broken up into smaller steps definedby, for instance, longitudinal translation vectors and rotation angles.The longitudinal translation vectors can define in which direction andby which amount the instrument should be moved in the respective stepand the rotation angles can define the rotations between respectiveportions of the instrument and the rotation of the entire instrument,which should be used in the respective step. For each intermediate stepthe corresponding motors can be actuated by the user and immediatefeedback from the position and shape reconstruction, i.e. the actualposition and shape of the instrument, can be used to compare theintermediate planned position and shape with the actual position andshape. If the intermediate planned position and shape differs from theactual position and shape by a given delta, the system may stop andrecalculate. At all times the user can make corrections to the targetposition and shape, i.e. the final desired target position and shape,and also to the intermediate target position and shape, which should beobtained after the respective intermediate step has been performed, forexample, by redefining it or choosing from alternatives. The user canalso choose to halt the actuation.

Although in above described embodiments the shapeable instrument is acatheter, in another embodiment the shapeable instrument can also beanother instrument like a needle. For a needle path the safety zones arepreferentially defined by nerve tissue, fat tissue and/or vessels.

The robotic system can be adapted to navigate the shapeable instrumentin any constraint environment, in particular, in any lumen within aperson or an animal. For instance, the robotic system can be adapted toprovide an endovascular, an endoluminal, a spinal cord, et ceteranavigation.

Although in above described embodiments the target position and shapeproviding unit is adapted to determine the target position and shapebased on the roadmap and the target region, in other embodiments thetarget position and shape providing unit may be adapted to allow a userto more directly define the target position and shape, i.e. not only bydefining the target region. For instance, the target position and shapeproviding unit can be adapted to allow a user to add markers to aroadmap or another kind of image like a computed tomography image or amagnetic resonance image showing the inner structure of the person andto determine the target position and shape of the catheter within theperson based on the added markers. For example, a user may add severalmarkers, which can be automatically connected by the target position andshape providing unit for determining the target position and shape.

Although in above described embodiments a roadmap is provided as theinner structure of the person, wherein the roadmap may have beendetermined based on a medical image like a computed tomography image ora magnetic resonance image, which may have been acquired before theinterventional procedure, in other embodiments the inner structureproviding unit can also be adapted to provide, for instance, a livethree-dimensional medical image like a live three-dimensional ultrasoundimage, which is acquired during the interventional procedure, whereinthe control unit can be adapted to control the robotic device based onthe inner structure shown in the live three-dimensional image, theactual position and shape of the instrument and the target position andshape of the instrument. This allows the control unit to considerchanges of the inner anatomy of the person, which may be caused by theinstrument within the person, during the interventional procedure.

Other variations to the disclosed embodiments can be understood andeffected by those skilled in the art in practicing the claimedinvention, from a study of the drawings, the disclosure, and theappended claims.

In the claims, the word “comprising” does not exclude other elements orsteps, and the indefinite article “a” or “an” does not exclude aplurality.

A single unit or device may fulfill the functions of several itemsrecited in the claims. The mere fact that certain measures are recitedin mutually different dependent claims does not indicate that acombination of these measures cannot be used to advantage.

Procedures like the determination of the target position and shape, theprovision of the inner structure, et cetera performed by one or severalunits or devices can be performed by any other number of units ordevices. These procedures and/or the control of the robotic system inaccordance with the robotic method can be implemented as program codemeans of a computer program and/or as dedicated hardware.

A computer program may be stored/distributed on a suitable medium, suchas an optical storage medium or a solid-state medium, supplied togetherwith or as part of other hardware, but may also be distributed in otherforms, such as via the Internet or other wired or wirelesstelecommunication systems.

Any reference signs in the claims should not be construed as limitingthe scope.

The invention relates to a robotic system for moving a shapeableinstrument like a shapeable catheter within an object like a person. Thesystem comprises a robotic device for modifying the shape of theinstrument and moving the instrument within the object and a controlunit for controlling the robotic device based on structure informationlike a roadmap, a target position and shape and an actual position andshape such that the instrument is moved and the shape of the instrumentis modified from the actual position and shape to the target positionand shape. Since the control unit considers structure information whilecontrolling the robotic device, the navigation of the instrument can beautomatically performed under consideration of knowledge about regionswithin the object, through which the instrument is navigatable. Thenavigation may therefore be performed without or with few userinteractions only.

The invention claimed is:
 1. A robotic system for moving a shapeableinstrument within an object, the system comprising: a robotic device formodifying the shape of the instrument and moving the instrument withinthe object, an inner structure providing unit for providing structureinformation about the inner structure of the object, a target positionand shape providing unit for providing a target position and shape ofthe instrument within the object, an actual position and shape providingunit for providing the actual position and shape of the instrumentwithin the object, and a control unit for controlling the robotic devicebased on the structure information, the target position and shape of theinstrument, and the actual position and shape of the instrument suchthat the instrument is moved and the shape of the instrument is modifiedfrom the actual position and shape to the target position and shape,characterized in that the inner structure providing unit is adapted toindicate safety zones within the inner structure, in which the roboticdevice should not apply forces larger than a predefined force value tothe instrument for at least one of modifying the shape of the instrumentand moving the instrument within the object, and further characterizedin that the control unit is adapted to control the robotic device suchthat no forces are applied by the robotic device to the instrument inthe safety zones larger than the predefined force value while the atleast one of the shape of the instrument is modified and the instrumentis moved from the actual position and shape to the target position andshape.
 2. The robotic system as defined in claim 1, wherein the roboticsystem further comprises a target region providing unit for providing atarget region to which the instrument is to be moved, wherein the targetposition and shape providing unit is adapted to determine the targetposition and shape of the instrument within the object based on thetarget region and the structure information.
 3. The robotic system asdefined in claim 1, wherein the target position and shape providing unitis adapted to allow the user to modify the target position and shape ofthe instrument.
 4. The robotic system as defined in claim 1, wherein theinner structure providing unit is adapted to provide a structure image,which shows the inner structure, as the structure information and thetarget position and shape providing unit is adapted to a) allow a userto add markers to the structure image and b) determine the targetposition and shape of the instrument within the object based on theadded markers.
 5. The robotic system as defined in claim 1, wherein thecontrol unit is adapted to control the robotic device only, if a userinputs a signal indicating that the control unit is allowed to controlthe robotic device based on the structure information, the targetposition and shape of the instrument and the actual position and shapeof the instrument.
 6. The robotic system as defined in claim 1, whereinthe actual position and shape providing unit is adapted to provide theposition and shape of the instrument by optical shape sensing.
 7. Therobotic system as defined in claim 1, wherein the actual position andshape providing unit and the control unit are adapted to provide afeedback loop during a movement of the instrument within the object,wherein the actual position and shape of the instrument is continuouslyupdated and the robotic device is continuously controlled based on thestructure information, the target position and shape of the instrumentand the updated actual position and shape of the instrument.
 8. Therobotic system as defined in claim 1, wherein the inner structureproviding unit and the control unit are adapted to provide a feedbackloop during a movement of the instrument within the object, and whereinthe inner structure of the object is continuously updated and therobotic device is continuously controlled based on the updated structureinformation, the target position and shape of the instrument and theactual position and shape of the instrument.
 9. The robotic system asdefined in claim 1, wherein the control unit is adapted to: determine aposition and shape plan defining a modification of the shape and amovement of the instrument, which is required for arranging theinstrument in accordance with the target position and shape, dependingon the structure information, the target position and shape of theinstrument and the actual position and shape of the instrument, andcontrol the robotic device in accordance with the determined positionand shape plan.
 10. The robotic system as defined in claim 9, whereinthe inner structure providing unit is adapted to provide a structureimage, which shows the inner structure, as the structure information,wherein element weights are assigned to elements of the structure image,and wherein the control unit is adapted to determine the position andshape plan such that a plan weight, which depends on the element weightsassigned to the elements of the structure image that correspond toregions within the object at least temporarily occupied by theinstrument when performing the position and shape plan, is optimized.11. The robotic system as defined in claim 9, wherein the control unitis adapted to determine several position and shape plans, wherein thesystem further comprises a display for displaying the determinedposition and shape plans together with the inner structure of the objectas defined by the provided structure information and wherein the controlunit is adapted to provide a user interface allowing the user to selectone of the determined position and shape plans and to control therobotic device in accordance with the selected position and shape plan.12. The robotic system as defined in claim 9, wherein the position andshape plan defines planned intermediate positions and shapes of theinstrument to be used while the shape of the instrument is modified andthe instrument is moved from the actual position and shape to the targetposition and shape, wherein the actual position and shape providing unitis adapted to continuously update the actual position and shape of theinstrument while the shape of the instrument is modified and theinstrument is moved in accordance with the position and shape plan, andwherein, during the modification of the shape of the instrument and themovement of the instrument in accordance with the position and shapeplan, the control unit is adapted to modify the position and shape planbased on the structure information, the target position and shape andthe updated actual position and shape of the instrument responsive to adeviation between an expected planned intermediate position and shape ofthe instrument and the updated actual position and shape of theinstrument being larger than a predefined threshold.
 13. A roboticmethod for moving a shapeable instrument within an object, the methodcomprising: providing structure information about the inner structure ofthe object by an inner structure providing unit, providing a targetposition and shape of the instrument within the object by a targetposition and shape providing unit, providing the actual position andshape of the instrument within the object by an actual position andshape providing unit, controlling a robotic device, which is configuredto modify the shape of the instrument and move the instrument within theobject, based on the structure information, the target position andshape of the instrument, and the actual position and shape of theinstrument by a control unit such that the instrument is moved and theshape of the instrument is modified from the actual position and shapeto the target position and shape, indicating safety zones within theinner structure, in which the robotic device should not apply forceslarger than a predefined force value to the instrument for at least oneof modifying the shape of the instrument and moving the instrumentwithin the object, and controlling the robotic device such that noforces are applied by the robotic device to the instrument in the safetyzones larger than the predefined force value.
 14. A non-transitorycomputer-readable storage medium in which computer-executable code isstored, the computer-executable code configured to cause a roboticsystem to: provide structure information about the inner structure ofthe object, provide a target position and shape of the instrument withinthe object, provide the actual position and shape of the instrumentwithin the object, control a robotic device, which is configured tomodify the shape of the instrument and move the instrument within theobject, based on the structure information, the target position andshape of the instrument, and the actual position and shape of theinstrument such that the instrument is moved and the shape of theinstrument is modified from the actual position and shape to the targetposition and shape, indicate safety zones within the inner structure, inwhich the robotic device should not apply forces larger than apredefined force value to the instrument for at least one of modifyingthe shape of the instrument and moving the instrument within the object,and control the robotic device such that no forces are applied by therobotic device to the instrument in the safety zones larger than thepredefined force value.